1. Field of the Invention
The present invention relates in general to liquid crystal display technology and, in particular, to liquid crystal light shutter display devices and associated media, which are capable of transmitting and scattering light in a reverse phase display mode or reverse mode liquid crystal (hereinafter sometime referred to as “RPDM” and “RMLC,” respectively). More specifically, the present invention relates to reverse mode liquid crystal display devices and associated media, which comprise organometallic chelates and nematic, negative dielectric anisotropic liquid crystal mixtures. Devices of the present invention can operate using low and/or non-lethal voltages, including less than approximately 24 volts, which is advantageous from a safety perspective relative to more conventional, high voltage systems, such as polymer dispersed liquid crystal devices (hereinafter sometime referred to as “PDLC”). Additionally, devices of the present invention can operate using AC and/or DC current, whereas older technology liquid crystal devices operated using only AC current.
2. Background Art
Liquid crystal display devices have been known in the art for several years. Furthermore, RPDM and/or RMLC devices are likewise well known. See, for example, U.S. Pat. No. 5,056,898 entitled “Reverse Mode Micro-droplet Liquid Crystal Light Shutter Displays,” U.S. Pat. No. 5,305,126 entitled “Polymer-Dispersed Liquid Crystal Material With In-Situ Polymerized Liquid Crystal Polymer Grains Dispersed In A Layer Of Liquid Crystal Material Sealed Between Substrates and Field Electrodes,” and U.S. Pat. No. 6,462,805 entitled “Reverse-Mode Direct-View Display Employing A Liquid Crystal Having A Characteristic Wavelength In The Non-Visible Spectrum,” all of which are hereby incorporated herein by reference in their entirety—including the references cited therein.
While the above-identified references disclose RPDM and/or RMLC devices, issues relative to liquid crystal media alignment, power consumption, unstable liquid crystal mixtures, and limited operating life have resulted in general obsolescence of the technology.
It is therefore an object of the present invention, among others, to provide a reverse mode liquid crystal display device which overcomes many of the aforementioned drawbacks associated with conventional RPDM and/or RMLC devices. The present invention utilizes a liquid crystal medium which comprises: (1) an organometallic chelate; and (2) a nematic, negative dielectric anisotropic liquid crystal mixture to overcome the problematic operational performance characteristics of conventional RPDM and/or RMLC devices.
These and other objects of the present invention will become apparent in light of the present specification, claims, and drawings.